1. Field of the Invention
The present invention relates to a display apparatus and a method to operate the display apparatus, and more particularly, to a display apparatus and method according to which ambient temperature of the display apparatus is measured and a backlight driving voltage of the display apparatus is controlled based on the measured temperature.
2. Description of the Related Art
In recent years, with increasing demand for display apparatuses, minimizing power consumption, which is directly related to duration of use, has attracted much attention. Generally, most portable devices with screens adopt a Liquid Crystal Display (LCD).
FIG. 1 is a block diagram of a conventional LCD backlight inverter system. Referring to FIG. 1, the conventional LCD backlight inverter system includes a video source device 100, a scaler 101, a timing control unit 102, an LCD 103 having a backlight 103-1, a luminance control unit 104, an inverter 105, a transformer 106, and a shut-down unit 107.
The video source device 100 generates a video source and processes the video source as displayable signals. The scaler 101 scales video signals including luminance signals from the video source device 100, and outputs the scaled video signals. The timing control unit 102 holds the video signals from the scaler 101 and outputs the video signals to the LCD 103. The luminance control unit 104 outputs a luminance control signal of the backlight 103-1 that lights the back of an LCD panel to make a screen of the LCD 103 highly visible. The inverter 105 generates a Pulse Width Modulation (PWM) frequency that controls the luminance of the backlight 103-1, and outputs the PWM frequency to the transformer 106. The transformer 106 transforms the PWM frequency from the inverter 105 to operate the backlight 103-1. When a problem occurs due to change in a backlight driving voltage, the shut-down unit 107 maintains a current applied to the backlight 103-1, and stops the operation of the inverter 105 to prevent any damage to the LCD backlight inverter system.
The conventional LCD backlight inverter system requires a high backlight driving voltage to turn the backlight 103-1 on at a low temperature. However, if the backlight driving voltage is too high at room temperature, when something inside the backlight 103-1 breaks or there is a problem with an input voltage, the shut-down unit 107 does not operate, causing damage to the LCD backlight inverter system. Generally, in order to avoid this problem, the backlight driving voltage is manually set to a predetermined value that does not cause a problem at both room temperature and at temperatures lower than the room temperature. Thus, because the backlight driving voltage does not correspond to the current temperature, the above mentioned problem still exists.